How do the scientists genetic engineer food?
They choose the desired traits they want to have in their food (more durable, bigger) and they then go about locating the specific gene inside another organism, plant or animal, and isolate this gene. After isolating it they then go about inserting it into the host using a vector, an organism that transfers genetic material. There are two types of vector, viral and plasmid. Viral vectors are simply viruses which have been injected with the chosen gene and injected into the host cell, they then go about replicating this gene in the host. Plasmid vectors are simply extra-chromosomal DNA molecules which replicate independently of a cell and have been spliced to incorporate the gene, they are then injected into the host cell and alter its DNA. All this is done as the host is a single cell organism and done on many cells, fully grown they are simply filtered out to discover if they had achieved the required results.
